1. Field of the Invention
The invention relates to a method of preparing stabilized aloe vera gel, and, more particularly, to a cold process for preparing aloe vera gel from the whole leaf that allows for both topical applications and internal applications.
2. History of the Prior Art
Aloe vera is a subtropical plant which has elongate leaves containing a clear, viscous gel. The leaves are given structural rigidity by means of a plurality of hair-like connective fibers which run throughout the leaf. The plant is the source of at least two medicinal substances which includes a mucilaginous yellow fluid which comes from the base of the leaves of the plant adjacent the leaf rind. This yellow fluid is known as aloin and has been used throughout history as an active ingredient in cathartics and medicinal purges. The other medicinal substance which comes from aloe vera is the clear gel taken from within the body of the elongated leaves. This gel has been used throughout history for its therapeutic healing effect on bums, insect bites, and other human and animal injuries.
The therapeutic efficaciousness of the clear gel taken from aloe vera leaves is a function of the freshness of the gel. For example, exposure of the gel to light and air for about 1 1/2 hours greatly diminishes the therapeutic power of the gel and may totally destroy it for some applications. For other applications, it has been found that relatively old, unstabilized gel has been effective. This difference is apparently a function of the fact that the gel itself is a complex mixture of components which are affected in varying degrees by exposure to air and light at different temperatures and which may vary from batch to batch of gel.
In addition to the decay of efficaciousness of the clear aloe vera gel upon exposure to light and air, the substance produces decomposition products which catalyze further decomposition over time. These phenomena render aloe vera gel extracts extremely difficult to compound into cream emulsions for topical applications. Cosmetic preparations of aloe vera usually become discolored after about four weeks and, further, the gel typically becomes rancid and totally unusable within the same time period.
One of the goals of prior art techniques of preparing stabilized aloe vera gel has been to preserve its medicinal efficacy as well as stabilize it for use in cosmetic preparations. The techniques taught in prior art U.S. Pat. No. 3,892,853 to Cobble and 4,148,372 to Coats have been relatively effective for many applications. However, both of these processes involve a step in which the temperature of the aloe vera gel and catalytic additives range from 35.degree. C. to about 80.degree. C. This addition of heat is necessary in order to destroy the aerobic bacteria within the gel and thereby sterilize it to inhibit decay. Most all of the organisms which cause decay in the therapeutic properties of the aloe vera gel are aerobic and, thus, without sterilization, the substance becomes rancid and essentially unusable within a relatively short period of time. The application of heat to the gel, however, also produces adverse side effects. Among these side effects are the fact that the heat destroys a substantial portion of the active ingredients within the gel and, thus, inhibits its efficacy as a medicinal compound. For example, heating of the gel contributes to the destruction of mucopolysaccharide as well as other enzymes and proteins which are believed to be responsible for a substantial portion of the therapeutic effects of aloe vera gel.
While processes for preparing aloe vera gel extract without the application of heat are known, see for example U.S. Pat. Nos. 4,735,935 and 4,851,224 to McAnalley, such cold processes have generally removed the outer skin of the aloe vera leaf before further processing. It is believed that the skin of the leaf, and the regions just below the skin, contain substantial quantities of highly active mucopolysaccharide compositions. Thus, fileting of the leaves to remove these regions results in a loss of efficacy of the final aloe vera product.
Other cold processes for preparing aloe vera gel extract are known which use the whole leaf of the aloe vera plant. However, these processes usually contain a chemical compound that is used for the purpose of killing bacteria. Due to the nature of these compounds, they have not been approved by the Federal Drug and Food Administration for internal consumption. This limits the gels and creams made from these processes to topical applications only.
Therefore, it can be seen that there is a need for a means for preparation of the purified aloe vera gel composition in both its untreated and hypoallergenic varieties without the application of heat that would allow retention of all of the valuable efficacious material contained within the region of the outer skin of the leaf. Furthermore, the provision of a cold process for preparing aloe vera gel from the whole leaf that could be taken internally would allow for greater diversification in the application of the final product.